Citation of any document herein is not intended as an admission that such document is pertinent prior art, or considered material to the patentability of any claim of the present application. Any statement as to content or a date of any document is based on the information available to applicant at the time of filing and does not constitute an admission as to the correctness of such a statement.
Biological samples/specimens, e.g., tissue sections or cells, are often mounted on microscope slides for examination. While on the slide, the specimens are often treated with one or more substances (e.g., dyes, reagents, etc.) to add color and contrast or microscopically labeled reagent to otherwise transparent or invisible cells or cell components. The treated specimens are often then covered with a thin transparent coverslip. This is done for several reasons. The coverslip can flatten the specimen so that the specimen is in the same viewing plane, thereby allowing one to view the specimen better. The coverslip provides protection for the specimen from the objective lens of the microscope should the lens be placed too closely to the slide. The coverslip (often in combination with an adhesive) further provides a housing structure or an area by which the specimen will be permanently retained on the slide to preserve for study and archiving purposes. The coverslip also helps to avoid contamination of the specimen.
The coverslip is typically a thin, rectangular, square or round piece of glass or plastic which is placed in direct contact with and over the specimen on the slide. The coverslip comes in a variety of sizes and shapes. One example of the coverslip has dimensions of about 1 in.×2 in. (25.4 mm×50.8 mm) and 0.005 in to 0.009 in (0.127 mm to 0.2286 mm) thick. They are often packaged stacked flat in a vertical pile. However, the coverslips are difficult to handle and separately remove from the stack as they are fragile and can stick together easily or break. To remove a coverslip from a stack, a considerable amount of bending moment is often applied to the coverslip. For example, previous systems, such as shown in U.S. Pat. No. 5,989,386 (Elliott), use two suction cup devices on a coverslip, placed on both sides of the middle of the coverslip. The suction cups thereafter bend the coverslip around a center element, creating great stress in the middle of the coverslip to separate it from the stack of coverslips. This action can result in numerous coverslips breaking because they are very fragile and the force applied was greater than the stability of the coverslip. The bending force causes a disproportionate amount of stress at the center of the coverslip. The bending action also does not guarantee that only one coverslip is selected.
Automated coverslippers have been used to mount glass coverslips on specimen-bearing microscope slides. However, such automated coverslippers can pick up more than one coverslip as they frequently stick together due to static forces, van der Waals forces, or moisture between adjacent coverslips. This may result in two or more coverslips being mounted on a slide. It may also be difficult to remove the excess coverslip(s) from the slide. If the automated coverslipper attempts to transport stuck-together slides, coverslips may drop resulting in loose coverslips in automated processing equipment. The loose coverslips can result in damage or malfunction of the automated processing equipment and may result in “downtime” for maintenance. Automated coverslippers are also not capable of accurately counting coverslips during handling. In addition, placement of the coverslip on the slide (often in the presence of a fluid, e.g., liquid adhesive) presents further problems. For example, it is important that no splashing occurs or no air bubbles be entrained between the coverslip and slide and become trapped under the coverslip when placed onto the slide. Examples of automated systems, such as shown in U.S. Pat. No. 7,271,006 (Reinhardt) and U.S. Pat. No. 7,727,774 (Reinhardt), use suctioning mechanisms for picking up and laying down a coverslip and a bending mechanism to assist in separating the coverslips. However, such devices can result in the unfortunate occurrence of bubbles that obfuscate subsequent analysis of the specimen on the slide.
Also, it is important not to harm the specimen in any way when positioning the coverslip onto the slide. One way to apply the coverslip is to place the coverslip on the slide, and then apply pressure onto the coverslip to compress and remove trapped air bubbles. However, handling and separating the coverslips at times can also charge them with static electricity. Electrostatic forces can hold the coverslip to the suction cups even after turning the mechanism off, making it difficult to apply the coverslip to the slide or discharge as the coverslip approached the slide causing one or more bubbles to form. Further, compression of the coverslip to remove air bubbles may cause the adhesive on the tissue sample to expel outward, thereby potentially contaminating other slides or other portions of the machine. Thus, there exists a need to provide a better automated coverslipper.
Thus, the art fails to provide an automated coverslipper and automated method of coverslipping with reduced bubbles and control of on-slide fluids. Nor does the current art provide an ability to configure or induce varied shapes in a coverslip that enable these advantages.